<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>变量</title>
</head>
<body>
    
</body>
<script>
    //实例1变量
    var num=520;
    alert(num.toString());//"520"
    var boo=false;
    alert(boo.toString());//"false")
</script>
</html>